In Joomla, you can customize the "Last-Modified" header by modifying the PHP code in the template's index.php file. Here's how to do it:
- Log in to your Joomla administrator panel.
- Go to the "Extensions" menu and click on "Templates".
- Click on the "Templates" submenu to see a list of all the templates installed on your Joomla site.
- Click on the name of the template you want to modify.
- Locate the index.php file for the template and open it in a text editor.
- Find the following line of code:
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
- Modify the date and time in the line of code to reflect the date and time you want to appear in the "Last-Modified" header.
- Save the changes to the index.php file.
- Refresh your Joomla website to see the updated "Last-Modified" header.
Note: It's important to keep in mind that modifying the "Last-Modified" header can have a negative impact on search engine optimization (SEO) if it's not done correctly. Before making any changes, it's a good idea to consult with a professional or consult with Joomla documentation to ensure you are following best practices.